Context: The Canadian-Australian IMPACT program has developed new ways to bring services to vulnerable communities. One approach, ‘Pop-Up’ health events, first trialled in Alberta, Canada, linked community-based health and social services with individuals who have poor access to needed care. Drawing on the Canadian model, two Pop-Up events were piloted in Melbourne, Australia. This study focuses on outcomes for participating organisations. Objective: To explore whether engagement with the Pop-Up model influences inter-organisational processes and collaboration between health and social service providers. Human Subjects Review: The study was approved by Monash Health (RES-19-0000-155L) and Monash University (20323) Ethics Committees. Design: Mixed method evaluation using a logic model and a pragmatic application of the RE-AIM framework. We performed structured observations during the Pop-Up events and held semi-structured interviews with consumers, providers, managers and our steering group. Providers completed pre-post surveys and an After Action Review. Setting: Community settings within disadvantaged areas of South-Eastern Melbourne. Participants: Managers and key staff from over 20 local health and social service organisations whose services matched the needs of the target communities. Intervention: Two Pop-Up events were held: one with people at risk of homelessness who were regular attendees at a community kitchen, and a second with South Sudanese women helping at-risk youth in their community. Outcome Measures: Survey outcome measures explored the impact of the intervention on inter-organisational processes and relationships. Our qualitative evaluation assessed providers’ experiences, acceptability and the perceived feasibility of broader implementation. Expected Results: Early analysis suggests that the Pop-Ups generated novel opportunities for providers to network, learn about local services, and prompted a range of ongoing collaborative initiatives. Results may be sustained through knowledge diffusion and ongoing inter-organisational contact, however, the continuation of the Pop-Up model faces challenges in funding and personnel. Conclusions: The Pop-Up model has shown promise in strengthening relationships between health and social service providers and reducing local network fragmentation in two international settings. These findings support the development of new, collaborative service delivery methods to best serve vulnerable communities.